


I Attempt Something that Isn't Swapcest (Kedgeup)

by SonicaSpeed123



Category: Undertale (Video Game)
Genre: Dom Papyrus, Fell Paps is a sweetheart guys, M/M, NSFW, Oneshot, Weird headcanons about how heats work, heat - Freeform
Language: English
Status: Completed
Published: 2017-05-09
Updated: 2017-05-09
Packaged: 2018-10-29 18:58:10
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,775
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10860057
Author URL: https://archiveofourown.org/users/SonicaSpeed123/pseuds/SonicaSpeed123
Summary: Why is it that whenever I sit down to write something it's always a Swapcest ideaTime to change that I guessUT Sans is in heat and needs his mancandy UF Pap to help him





	I Attempt Something that Isn't Swapcest (Kedgeup)

Sans groaned and pushed his body further into the mattress, trying to muffle himself as well as his suffering.  This damned heat was starting to get  _ really _ bad.  Another pulse of burning desire rippled out from his soul, making him wince and freeze up until the wave had passed.  When it did, his body relaxed again, or about as much as it could in this state.

“fuck… fell-” he cried out, desperate for his lover, “hngh… need you…”

As if on cue, he heard the sound of someone bounding up the stairs and heading toward his room.  Before his mind could catch up and take action to tell the visitor to leave, they had already knocked on his door.

“Sans? It’s your brother… Are you doing alright?”

Oh. Maybe Fell wouldn’t show up.  That was… kind of bittersweet, he supposed.  He was less likely to embarrass himself that way, but his little problem would still go unsolved.

“n-not really, bro. i need some time alone right now. not feeling the greatest.”

“Oh. Should I tell the other me to go home, then? I think he’d be very helpful…”

Shit. But also, thank god. How did his brother know he was in heat?  Fuck, his scent probably travelled through the whole house by now.  If Fell was already there, he’d know he was in heat the moment he stepped inside.

“Um, Sans? I’ll just send him in.”

“...fine…” he sounded hoarse and defeated, ashamed to let his desires control him. But he wasn’t too ashamed.  God, he needed this.  Even if he didn’t want to admit it.

He heard Papyrus go down the stairs again, then about a minute later, someone came back up again.  Someone who was distinctly wearing heels- Sans smiled at the thought of Fell struggling up the steps in his favorite (and outrageous) shoes, but trying to play off his clumsiness as completely intentional.  The smile vanished as another wave of lust hit him. He bit down on his pillow and moaned, praying that Fell couldn’t hear him yet.

He froze when he heard the knock on the door, mortified.

“Sans? Sans, it’s your boyfriend! Your brother said you needed help..?”

Sans caught his breath and attempted to sound coherent, “h-hey, uh… thanks for cumming-  _ stopping _ , stopping by, b-but i’m just feeling a little under the weather, heheh… i don’t want you to get dick-  _ sick _ , i meant-”

“I know you’re in heat, sweetie. And I’ll ignore those puns just this once. May I come in so I can assist you?”

The thought of what “assistance” entailed pushed Sans to answer, “yeah. please…”

Fell acted out of character and opened his bedroom door slowly, peeking in before entering completely.  The look on his face was one of concern, but he held a weak smile of reassurance as well.

“Oh, dear… You’re a wreck…”

Sans was almost surprised at his own laugh, “gee, thanks-  _ ah- _ !” He was forced to grip his sweaty shirt, desperate to calm his soul.  Fell’s presence was definitely what his body had been waiting for.  It was too much to deny anymore. “oh my god, please, fell-”

-Was he smirking now?  Christ, knowing him, he was probably taking _ immense _ pleasure in this.

“Of course, sweetie.  What do you want me to do to you?”

_ Anything. Everything. _ “j-just touch me… i need you…”

Fell hummed lowly as he gently closed the door, then sat next to Sans on his mattress.  Instantly, Sans rolled over to cling to him.

“I need to remove your clothes, darling.”  Sans could  _ hear _ the smirk in his voice.

Right, right. Duh.  Sans hesitated before separating from Fell.  He made quick work of pulling off the sweat-drenched tank top and shorts, but the slight grazing touches against Sans’s bones were inevitable.  He had to lock his jaw to prevent his voice from going anywhere.

Fell noticed quite easily.  “Don’t worry.  Your brother left when I came in.  You can be as loud as you like.” He moved over Sans, who was still silent, “I wonder what he ran off to? Or, perhaps,  _ who _ ..?” he teased.

“mh?”

Fell chuckled quietly, “Did you know that your cycle lines up with my brother’s?”

Sans was confused for a moment, needing a few seconds for his cloudy mind to connect the dots.

“oh my god.”

“I thought you might like to know.”

“i’ll kill that bastard-”

“You will do no such thing,” Fell commanded.  Sans immediately went silent again as his body warmed at his tone, “Your heats are very similar.  And he loves your brother.  He couldn’t harm him if he tried.  Besides, it isn’t even his fault.  You know very well that one can’t control their own cycle.”

“...yeah, guess so… mh, i’ll chat with him later. don’t wanna think about it now.”  Fell was surprised.  Usually he was much more stubborn.

“Good boy,” Fell brought his hand up to stroke Sans’s chin, “Just focus on me now, baby.”

“--hah- yessir-” Sans said with a groan.

“‘Sir’? I like that,” Fell finally ground his hips down, “Keep talking as long as you can.”

“ah-! ahn, sir, please, more-!”  Sans clutched at Fell’s torn scarf, pulling him down so he could invade his mouth with his tongue.  Fell was intrigued by the strange power balance of the situation- he was on top, and he was doing everything, but it was increasingly clear that Sans was the one calling the shots.  It probably wouldn’t be that way for long, though- monsters in heat tended to go quiet when they reached a certain point of pleasure; then he wouldn’t be able to ask (or beg) Fell to do anything.

Suddenly, Sans jerked his head away from the kiss to expose his neck. “bite-” he cried out with raspy breath.

Fell followed orders without hesitation (perhaps he was more submissive than he had originally thought) and sank his teeth into the soft cartilage between his vertebrae.  He reveled in the gasp and drawn out moan that followed.

“fuck-! please, please, sir, i need-”

As Fell nursed the bite wound he had created, he moved his hands down to stroke at Sans’s sensitive spots- his lower ribs would settle for now.  Sans tried to grind his hips up into Fell’s, but he was still wearing his pants.  Sans whined at the lack of friction where he needed it.

“Ssh, ssh, I know…” Fell mumbled into Sans’s neck, “I’ve got you.”  Fell managed to sit up enough to undo his belt and pull his leather pants off, carefully monitoring Sans’s expression.  He looked desperate- and he was- and breathed shakily as Fell’s pelvis was finally freed from its leather prison.  Sans was hit with one final wave of agonizing desire, throwing his head back and groaning loudly.

“please- oh stars, please-”

The next thing he knew, there were fingers in his cunt.

He cried out as the pain from his lust quickly melted into intense pleasure, pushing his hips up into Fell’s hand, begging for more, deeper, faster.  Fell couldn’t help but obey every request, watching breathlessly from on top of him.  He had barely noticed that his magic had become active.

Barely.

But he’d have a chance to use it later.  He needed to conserve his energy.  Who knew how many times it’d take to bring his boyfriend out of heat?  For now, he slipped in another finger.

“How’s three, dear? Need more?”

“more, need- sir, _ sir, need--!! _ ” Fell pumped in and out a few times before adding another finger and using his other hand to rub at his oversensitive clit.  Without warning, he felt Sans’s walls tighten around his fingers as he came with a scream.  Fell turned his head to kiss his boyfriend and gently removed his hand, feeling Sans’s excess magic flow out of him.

For a few moments, they sat in silence, recovering.  If he didn’t know any better, he’d think that Sans had fallen asleep- but heated monsters couldn’t sleep.  He showered his sweaty lump of a lover with kisses and praise.

“That’s it, beautiful.  You did so well.  I’m going to make you feel so good…”

“ahn- i love you…”

Fell smiled, “I love you, too.  Do you need to go again?  I’ll do whatever you need.”

“yeah, more…”

“What do you want?”  Fell asked patiently.

“ngh…”  Sans reached between Fell’s legs.  Fell almost jerked away in surprise, but quickly decided against it as Sans’s fingers tugged on his shaft.  He panted when Fell groaned.

“-Alright then.”  Fell quickly shifted so his dick was pressed just outside of Sans’s entrance. “Are you ready for me?”

Sans frantically nodded.

“Gone quiet already?  Hm.  You remember our tapout, yes?” Another nod, “Good.  Not that you’ll want to use it anyways, but just in case.  If you’re sure you’re ready…”  He guided his cock into his boyfriend gradually but easily, his cunt still wet and slick from his last orgasm.  He moaned as he was surrounded by the wet warmth and had to hold back from thrusting too hard right away.

Stars, the  _ sounds _ Sans made… He couldn’t speak, but  _ god, _ could he moan.  His voice climbed and climbed in pitch and volume, his eyelights going fuzzy as he lost focus.  Eventually, he couldn’t go much higher, and his voice cracked.

“Ah- We’ve barely even started, dear- Nnn-! D-do you want it faster..?”

“nn-hn-!” He grunted affirmatively, clutching at Fell’s pelvis, trying to force him to move faster.  Fell easily followed the slightly pushy command, allowing himself to reach the speed he had wanted to go in the first place.

Sans’s walls began spasming around Fell’s cock in an  _ exquisite  _ way, overwhelming him.  Fell buried his face in the crook of Sans’s neck to steel himself, forcing himself to focus on biting and kissing instead of how damned close he was to cumming.

Sans writhed underneath him, unsure of what to do with his body.  His mind was too hazy, his thoughts disconnected.  Eventually, his instincts settled on wrapping his arms and legs around his mate as tightly as possible.

Suddenly, Fell broke his head away, gasping and grunting with every thrust, speeding up even more than before.

“God,  _ god _ , I  _ can’t- _ Too much, too  _ good- Ahn, _ I’m cumming, baby,  _ cumming _ , where do you want it, where-  _ Hah-!! _ ”

Sans could barely whisper, his voice nearly completely shredded, but he was desperate enough to squeak out, “ _ ‘nside- in- inside, cum-! _ ”

Fell came with a gorgeous wail, filling his lover all at once.  Sans followed immediately afterwards, the feeling of Fell’s cum inside him pushing him into a state of ecstasy.  Their bodies were jerky, then tense, then finally, they both collapsed.

**Author's Note:**

> And then they fucked for like 5 hours
> 
> Why are all my nsfw fics the longest ones???


End file.
